Piston construction



May 4, 1965 F. c. DRUzYNsKl 3,181,514

PISTON CONSTRUCTION Filed Nov. 21, 1963 2 Sheets-Sheet 1 42 28 I6 i8 39 28` f J7 f l 36 I0 30- 34": j K/ 44 I 24A 32 I 22 FIG. 26 24 2 ATTORNEYS May 4, 1965 F. c. DRuzYNsKl PISTON CONSTRUCTION 2 Sheets-Sheet 2 Filed NOV. 2l, 1963 FIG. 3.

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INVENTOR FRANK C. DRuzYNsm BY @LLM ATTORNEYS United States Patent O 3,181,514 PISTON CNSTRUCTON Frank C. Druzynsld, Bloorneld Hills, Mich., assigner to Continental Aviation and Engineering Corporation, Detroit, Mich., a corporation of Virginia Filed Nov. 21, 1963, Ser. No. 325,272 4 Claims. (Cl. 12S-41.35)

The present invention relates to internal combustion engines and more particularly to pistons for such engines having means for cooling the piston in the vicinity of Ithe piston ring grooves.

The present invention is especially applicable to those internal combustion engines in which the combustion chamber is arranged entirely or substantially within the face of the piston although as the description proceeds it will be apparent that the present invention will be suitable for other types of pistons as well.

The advantages of providing the combustion chamber within the face of the piston have been known for some time. The most desirable shape for such a chamber has been found to be a nearly hemispherical hollow space or cavity extending well into the face of the piston.

One of the problems encountered in such pistons is that the relatively thin wall which separates the combustion chamber from the ring groove area readily transmits heat produced in the chamber to the area of the ring grooves. High temperatures especially in the area of the top ring groove tends to produce fuel deposits which will eventually cause the piston rings to Score the walls of the cylinders.

A copending application, Serial No. 325,271, tiled November 2l, 1963, by Walter F. Isley, discloses and claims pistons provided with means for cooling the ring groove area of the piston head. The present invention provides an alternate method of constructing such pistons.

It is an object then of the present invention to reduce fuel deposits in the vicinity of the top ring groove of pistons for internal combustion engines by providing means for cooling this area of the piston during operation of the engine.

It is another object of the present invention to increase the eticiency of internal combustion engines by providing a cavity in the piston head for such engines positioned closely adjacent the top ring groove thereof and means for circulating oil through Ithe cavity.

lt is still another object of the present invention to simplify the manufacture of pistons having an annular cooling cavity provided in the head thereof by providing a ring member adapted to seat in the cavity and providing support for a weld to close the cavity.

Still further objects and advantages of the present invention will be readily apparent to one skilled in the art to which the invention pertains upon reference to the following drawings in which like reference characters refer to like parts throughout the Several views and in which FIG. 1 is an elevational top view of a piston of the present invention.

FlG. 2 is a cross sectional view taken substantially at line 2 2 of FIG. 1.

FIG. 3 is a fragmentary cross sectional View taken substantially on line 3 3 of FIG. 1 with portions shown schematically for purposes of clarity, and

FIG. 4 is an enlarged cross sectional view of a ring member of the present invention.

Description Now referring to the drawings for a more detailed description of the present invention a preferred piston l is illustrated as having a head portion 12 and a skirt 1.4.

The head portion 12 is provided with a planar face 16. A substantially spherical combustion chamber cavity 18 is provided in the face 16 and extends well into the head portion 12 as shown. A groove 2h is formed in the face 16 as can lbest be seen in FIG. 1 to direct fuel from an injection nozzle (not shown) into the combustion chamber cavity 18.

The substantially annular exterior .surface 22 of the head portion 12 is provided with a plurality of axially spaced ring grooves 24 and a top ring groove 24A. Each of the grooves 24 and 24A is adapted to carry a conventional piston ring (not shown).

The face 16 is provided with an axially extending annular recess indicated generally at 26. The recess 26 comprises an upper portion preferably formed by angularly inwardly extending walls 28, a radially elongated medial portion 3i) and an axially extending elongated lower portion 32.. An annular shoulder 34 is formed intermediate the medial portion 30 and the lower portion 32.

A ring member 36 as can best be seen in FIG. 4 preferably comprises an axially extending ange portion 38 and a radially extending flange portion 49. The ring member 36 is adapted to be inserted in the recess 26 and the axially extending ilange portion 38 is provided with an annular seat portion 40 complementary to and adapted to engage with the shoulder 34. The radially extending ange portion 49 extends across the recess 26 and is adapted to be wedged into position engaging a corner portion 39 formed in one of the walls 28. With the ring member 35 in the position described a suitable welding material 42 is used to till the recess 26 above the ring member 36. In this way an annular cavity 44 is provided in the head portion 12 in a position intermediate the cornbustion chamber cavity 18 and the area of the ring grooves 24E-24A. The cavity 44 extends at least below the plane of the top ring groove 24A.

The skirt 14 is preferably hollow as shown to provide a substantailly annular recess 46. Wrist pin bosses 48 extend radially inwardly from opposite sides of the recess 46 and are provided with axially aligned openings S0. The openings Sil are adapted to receive a wrist pin (not shown).

As can best be seen in FIGS. l and 3 a conical inlet 52 is provided in the head portion 12 intermediate the recess 46 and the cavity 44. The inlet preferably has the larger cross sectional portion thereof in registry with the recess 46 and opens high in the cavity 44. An outlet 54 is also provided in the head portion in a position spaced from and substantially opposite the inlet 52. The outlet 54 provides communication between the lower portion of the cavity 44 and the recess 4d. A nozzle 56 directs a stream of oil delivered by the oil pump 58 into the conical inlet 52.

In operation oil is delivered from the oil pumping system of the engine and 'by the nozzle 56 through the inlet S2 and into the cavity 44. The conical shape of the inlet 52 insures that the major portion of the oil will reach the cavity 44 regardless of the axial position of the piston lil. The inlet 52 being positioned high in the cavity 44, prevents the oil from escaping through the inlet 52 and the reciprocating movement of the piston 10 during operation of the engine will result in the oil being moved annularly through the cavity 44 and out the outlet S4. This provides a substantial cooling of the piston especially in the area of the top ring groove 24A. By reducing temperatures in this area, ring groove deposits are substantially eliminated since a temperature is maintained below the colting temperature of the fuel being used to operate the engine.

In the particular embodiment disclosed, it has been preferred to construct the ring member 36 of copper although it is apparent that other materials can be used.

' :glaner/i The piston herein disclosed provides a simple construction 2. The assembly as dened in claim l and including for providing a cavity in the head of a piston and one means circulating a coolant through said annular cavity. which produces a relatively economically produced piston 3. The assembly as dened in claim l and in which having such a cavity. (a) said annular surface is provided with a plurality Although I haverdes'cribed a single embodiment of the 5 Vof axially spaced piston ring grooves, Y present invention, it is apparentV that many changes and (b) said annular cavity being positioned closely adrnodications can be made Without departing from the jacent said piston ring grooves, and `spirit of the invention as expressed by appended claims. (c) means circulating a coolant through said annular I claim: cavity whereby to cool the area of said head portion 1. In an internal combustion engine a piston assembly lo havino said piston ring grooves. comprising Y 4. The assembly as defined in clairnV and in which (a) a piston member having a head portion, Said circulating means comprises, Y (b) said head portion being provided With a top (a) an inlet provided in saidV head portion and registerplanar surface and an annular surface extending on ing with said annular cavity, an axis substantially normal with respect to said top 15 (b) an outlet provided in said head portion substantial-- Y surface, ly radially opposite said inlet, and (c) a combustion chamber cavity extending into said (c) means adapted for connection with the oil supply head portion from said top surface, system of said engine and operable .to deliver a (d) an annular cavity being provided in said head porstream of oil to said inlet.

tion intermediate said combustion chamber cavity 20 and Said annular Surface, References Cited by the Examiner (e) an annular recess being provided in said top sur- UNITED STATESV PATENTS face in registry with said annular cavity, Y (f) said cavity being provided with lan enlarged por- 2800119 7/57 Schmldt 12?41'35 tion to form a radially extending shoulder portion g5 FOREIGN PATENTS and a corner portion spaced radially inwardly from 1,246,794 10/60 France' Sald Shoulder PONG, 1,001,862 1/57 Germany. (g) a ring member having a portion seated on said 1,019,519 11/57 Germamh Y shoulder portion and a radially extending flange por- 1,025,221 2/58 Germany tion adapted to be wedged against said corner por- 30 892,489 10/58 Great Britain` tion, and i (h) said recess above said ring member being lled with RICHARD B WILKINSON Prlmm'y Exammea Welding material whereby toV cls said cavity. i KARL J, ALBRECI-ITs Examiner, 

1. IN AN INTERNAL COMBUSTION ENGINE A PISTON ASSEMBLY COMPRISNG (A) A PISTON MEMBER HAVING A HEAD PORTION, (B) SAID HEAD PORTION BEING PROVIDED WITH A TOP PLANAR SURFACE AND AN ANNULAR SURFACE EXTENDING ON AN AXIS SUBSTANTIALLY NORMAL WITH RESPECT TO SAID TOP SURFACE, (C) A COMBUSTION CHAMBER CAVITY EXTENDING INTO SAID HEAD PORTION FROM SAID TOP SURFACE, (D) AN ANNULAR CAVITY BEING PROVIDED IN SAID HEAD PORTION INTERMEDIATE SAID COMBUSTION CHAMBER CAVITY AND SAID ANNULAR SURFACE, (E) AN ANNULAR RECESS BEING PROVIDED IN SAID TOP SURFACE IN REGISTRY WITH SAID ANNULAR CAVITY, 